Sandy Creek Generating Station – Grey Water Lime Softening System
Project Overview
The Sandy Creek Generating Station is a 900-MW coal-fired power facility featuring a supercritical pulverized coal boiler, tandem compound reheat steam turbine, SCR system, dry scrubber, and baghouse. Designed to operate on Powder River Basin (PRB) coal, the plant incorporates an innovative grey water reuse system—treating reclaimed domestic wastewater for process and cooling tower use.
To ensure consistent water quality for process operations, the facility required a lime softening system to reduce hardness and remove impurities prior to secondary treatment.
Challenge
Treating reclaimed grey water presents unique challenges, including high hardness, iron, heavy metals, and potential biological contaminants. The goal was to create a reliable pretreatment process that would enhance downstream reverse osmosis (RO) efficiency while meeting strict plant water quality requirements.
ClearStream Solution
Working in partnership with the system OEM, ClearStream Environmental supplied key components of the lime softening system, including:
- (2) 80-ft Diameter Solids Contact Clarifiers (5,250 GPM each)
- (1) 50-ft Diameter Sludge Thickener
Following lime softening, a recarbonation step using acid or CO₂ was implemented to stabilize pH and prevent post-precipitation of calcium and magnesium.
The overall system also included multimedia filters, lime feeders, chemical feed systems, and sludge dewatering—ensuring complete treatment of the reclaimed water for safe reuse within the power plant.
Results
The lime softening system successfully reduced hardness, removed heavy metals and iron, and improved RO performance. Additional benefits included pathogen reduction, enhanced water quality, and reduced maintenance for downstream equipment.
By combining engineering expertise, flexible design, and competitive pricing, ClearStream proved to be a trusted partner for OEMs, engineers, and contractors seeking custom water treatment solutions for power generation and industrial applications.
Resources and Related Links
Sandy Creek Generating Station – Grey Water Lime Softening System
Equipment in this Case Study